5 Things to Check Before Buying a Kei Truck

Kei trucks are durable, capable little machines. But they are also 25+ year old vehicles that have spent their lives working in Japan, and not every example is worth buying. The difference between a solid truck that will serve you for years and a money pit that drains your wallet is often visible during a thorough pre-purchase inspection.

Whether you are buying from a dealer, a private seller, or evaluating auction photos before an import, these five checks will help you separate the good trucks from the ones you should walk away from.

1. Rust: The Number One Killer

Rust is the single most important factor in evaluating any imported kei truck. Japan has aggressive road salt programs in its northern prefectures (Hokkaido, Tohoku, and parts of the Japan Sea coast), and trucks that spent their lives in these regions can have severe corrosion that compromises structural integrity.

Where to look:

• Frame rails: Get under the truck and inspect the full length of both frame rails. Surface rust is normal and manageable. Flaking, scaling, or through-rust on the frame rails is a deal-breaker. Poke suspect areas with a screwdriver — if it goes through, walk away.
• Cab corners and rocker panels: These are the first body panels to rust on any kei truck. Look for bubbling paint, filler, or fresh undercoating that might be hiding corrosion.
• Bed floor: Stand in the bed and flex the floor with your feet. A solid bed will feel rigid. A rusty bed will flex and may show holes, especially around the edges and near the tailgate hinges.
• Wheel arches: Both front and rear wheel arches trap mud and salt spray. Inspect from above and below.
• Cab floor (under the floor mats): Pull up the rubber floor mats and inspect the steel floor, particularly around the pedals and under the seats where the engine heat meets road spray.

Pro tip: If the truck has been freshly undercoated, be extra skeptical. Fresh undercoating on a 25-year-old truck is often applied to hide rust, not prevent it. Ask why it was applied and try to inspect beneath it.

Auction sheets: If buying from Japan, the auction sheet will grade the undercarriage condition. Grades of "C" or "D" on the undercarriage indicate significant corrosion. Grades of "B" or better are what you want.

2. Engine Health: Compression, Leaks, and Smoke

Kei truck engines are small, simple, and generally reliable. But at 25+ years old, worn engines are common, and a rebuilt 660cc engine is a disproportionately expensive repair relative to the truck's value.

Cold start test: If possible, start the engine from cold. A healthy kei truck engine should start within 1-3 cranks, idle smoothly within 30 seconds, and not produce excessive smoke. Difficulty starting from cold can indicate weak compression, a failing starter, or fuel delivery issues.

Exhaust smoke:

• White smoke on cold start that clears: Normal condensation, not a concern.
• White smoke that persists: Coolant entering the combustion chamber, likely a head gasket issue. This is expensive on all kei trucks and particularly labor-intensive on mid-engine (Honda Acty) and rear-engine (Subaru Sambar) models.
• Blue smoke: Oil burning, indicating worn piston rings or valve seals. The engine is on borrowed time.
• Black smoke: Running rich, typically a carburetor or fuel injection issue. Usually fixable but worth negotiating on price.

Compression test: If you are buying locally and have access to the truck, a compression test is the single most valuable diagnostic you can perform. All cylinders should read within 10% of each other and above 120 PSI. Low or uneven compression indicates worn rings, valve issues, or head gasket problems.

Oil condition: Pull the dipstick. Clean oil at the correct level indicates an owner who maintained the truck. Milky oil (coolant contamination), very dark and gritty oil (neglected changes), or oil significantly above the full line (overfilled or fuel dilution) are all red flags.

Coolant check: Open the radiator cap (when cold) and inspect the coolant. It should be a consistent color (green or pink depending on the type) without oil slicks, rust particles, or a foul smell. Brown or rusty coolant indicates a neglected cooling system. An oily film on the coolant surface suggests head gasket failure.

3. Drivetrain: 4WD, Transmission, and Clutch

A kei truck with a bad transmission or a non-functional 4WD system loses much of its utility. These components are expensive to repair and parts can be difficult to source.

4WD engagement: With the truck stationary or rolling slowly, engage 4WD. It should engage cleanly without grinding or excessive clunking. Once engaged, drive in a circle on a dry surface — you should feel the front wheels pulling. If the truck drives identically in 2WD and 4WD, the system is not engaging.

Low range: If the truck has selectable low range, test it. Shift into low range and confirm a noticeable reduction in speed with increased torque. Low range is essential for heavy off-road use, and a non-functional low-range transfer case is an expensive repair.

Manual transmission: Drive through all five gears. Each gear should engage smoothly without grinding. Pay attention to second and third gears, which wear first. Check for gear pop-out — if the truck jumps out of a gear under load or deceleration, the synchros or shift forks are worn.

Clutch: The clutch pedal should have a defined engagement point with smooth take-up. A clutch that engages very close to the floor (at the top of pedal travel) is nearing the end of its life. A slipping clutch will cause the engine to rev without corresponding acceleration, particularly in higher gears under load.

Automatic transmission (if applicable): Check for smooth shifts between all gears, no slipping, and no harsh engagement when shifting from Park to Drive. Check the transmission fluid: it should be pink or red and not smell burnt. Dark, burnt-smelling fluid indicates internal wear.

Differential noise: With the windows down, listen for whining, clicking, or grinding from the rear differential during driving. A quiet differential is a healthy one.

4. Electrical System: Lights, Gauges, and Charging

Kei trucks have simple electrical systems, but 25+ year old wiring can develop issues that are tedious to diagnose and repair.

All lights: Check headlights (high and low beam), tail lights, brake lights, reverse lights, turn signals, and hazard lights. Non-functional lights are usually bulbs or grounds, but widespread electrical failures can indicate deeper wiring issues.

Gauges: Start the engine and verify that all gauges work: speedometer, tachometer (if equipped), fuel gauge, temperature gauge, and oil pressure light. A temperature gauge that does not move or stays pegged high may indicate a bad sender, but it could also be masking a cooling issue.

Charging system: With the engine running, the battery voltage should read 13.5-14.5 volts (if you have a multimeter). A voltage reading below 13 volts indicates the alternator is not charging properly. Alternator failures are common on older kei trucks, especially Daihatsu Hijets.

Wiper and heater: Test the wipers and heater fan at all speeds. A non-functional heater is miserable in cold weather, and the heater core on a kei truck is buried deep behind the dashboard.

5. Suspension, Steering, and Brakes

These are safety-critical systems that can be expensive to overhaul.

Bounce test: Push down firmly on each corner of the truck and release. The truck should bounce once and settle. Multiple bounces indicate worn shock absorbers.

Steering play: With the engine running, rock the steering wheel back and forth. There should be minimal free play before the front wheels start to move. Excessive play indicates worn steering box components or tie rod ends.

Steering while driving: The truck should track straight on a flat road with hands lightly on the wheel. Pulling to one side indicates alignment issues, a dragging brake caliper, or uneven tire wear.

Brake test: From 20-30 mph, apply the brakes firmly. The truck should stop straight without pulling to one side, and without grinding, squealing, or pulsation. Pulsation indicates warped rotors. Grinding indicates worn-through brake pads. Pulling indicates a seized caliper or uneven pad wear.

Leaf spring inspection: Kei trucks universally use leaf springs at the rear. Inspect for cracked, broken, or sagging leaves. A truck that sits noticeably lower on one side likely has a broken leaf spring.

Ball joints and tie rods: Jack up the front of the truck and grab each front wheel at 12 and 6 o'clock, then at 3 and 9 o'clock. Rock the wheel in each direction. Any clicking or noticeable play indicates worn ball joints or tie rod ends.

The Bottom Line

A thorough pre-purchase inspection takes 30-45 minutes and can save you thousands of dollars in surprise repairs. The most important rule is simple: never fall in love with a truck before you inspect it. Kei trucks are plentiful and more are imported every month. If one truck fails the inspection, the next one might be perfect. Walk away from a bad truck with confidence, because a good one is out there waiting. For model-specific issues to watch for, check our guides to the Suzuki Carry, Honda Acty, and Mitsubishi Minicab. Once you've found your truck, our kei truck parts guide will help you source replacement parts.

If you are buying remotely (through an importer or at auction), communicate these inspection priorities to the seller and request detailed photos or video of every area listed above. A seller who will not provide undercarriage photos or a cold-start video is a seller to avoid. Browse our dealer directory to find trusted kei truck dealers and importers near you.